Three Common Compound Tuning Questions

Below are three common questions students often ask when it comes to compound bows.

QUESTION 1

"I recently purchased a compound bow and I don't know how to adjust the draw length. How do I do that?"

It varies on the individual compound bow, but basically it is a matter of reading the owner's manual and then following the instructions. There are however common

Step one will typically be to unscrew the top limb bolt (where the limb meets the riser) using an Allen key / hex key. Doing so lowers the poundage of the bow on the top limb. Start by rotating the key 2 full circles.

Step two, unscrew the bottom limb bolt 2 full rotations.

Step three, repeat step one and step two until the limbs are at their maximum lowered poundage. Keep track of how many full rotations you used for both top and bottom limbs.

Step four, consulting your owner's manual adjust the pins on your top and bottom cams to the desired settings for the draw length.

Step five, rescrew the bottom limb 2 rotations, then the top limb 2 rotations, and keep repeating this process until both top and bottom limbs are back at the original settings (so the draw weight is once again returned to the same amount).

QUESTION 2

"How do I adjust the draw weight?"

 If you already read the answer to Question One, this part will be easy. You adjust the draw weight by either unscrewing or screwing both the top and bottom limb bolts equal amounts until you get to your desired draw weight.

You will want to use a draw weight that you can pull back easily. If you feel like you are going to rip your muscles or that it is almost impossible to full back, then it is too heavy for you and you should lower it to a more manageable draw weight.

Note - For hunting purposes you would still need to use a draw weight that is equal to or above the legal minimum for your prey. eg. In Ontario the legal minimum for deer is 39.7 lbs, and for moose / elf / black bear the legal minimum is 48.5 lbs.

Determining the precise draw weight requires a gadget to measure to the draw pull at "the Wall" (the point at which the draw weight while pulling back is at its highest point). Most archery stores have such a gadget on hand and can tell you the precise draw weight when they setup your bow for you. Experienced archers can also estimate the draw weight of your bow just by pulling it back and giving their best guess based on their past experience.

QUESTION 3

"How do I adjust the sights on my compound bow?"

For this one you really should sign up for an archery lesson. Beginners have a tendency to make all sorts of mistakes when adjusting the sights on their compound bow so it is a case wherein you are best guided by someone who has experience adjusting the sights to help tune your compound bow so you get the utmost accuracy out of your equipment.

The short answer to this question is to make clusters of arrows on the target and then 'chase the cluster' by adjusting your sights in whatever direction(s) the cluster is in. Adjusting the sight is counter-intuitive. You have to adjust the sight in the direction of the cluster. Many beginners think if your shots are too high that you need to lower the sight. It is actually the opposite, you need to raise the sight upwards and then your arrows will go lower. Raising the sight lowers the trajectory angle of the arrow, lowering the sight raises the trajectory angle of the arrow. Huzzah for physics lessons.

Fine tuning the sights up/down and left/right is more complex than that however so if you have a friend who has experience tuning compound sights, I strongly recommend you ask them to help you out - or if you live in Toronto you can hire an archery instructor like myself.

Sometimes people also install other parts on compound bows improperly and they need to be adjusted first before you adjust the sight. For example the arrow rest should be tuned first, before you tune the sight. eg. I once met someone shooting a right-handed bow with a left-handed bow's arrow rest installed backwards on it. That was a case in which they needed a right arrow rest first, install it, tune it, and then they can start tuning the sights.